A CLINICAL-TRIAL OF RECOMBINANT BOVINE INTERFERON-ALPHA(1) FOR THE CONTROL OF BOVINE RESPIRATORY-DISEASE IN CALVES

The effects of recombinant bovine interferon alpha1 (rBoIFNalpha1) on the incidence of bovine respiratory disease (BRD) were examined in 60 young male cattle. Each group of clinically healthy 30 male cattle was injected intramuscularly with either rBoIFNalpha1 (5 mg/head) or phys iological saline 5 times in 6 months. They were examined daily for the clinical symptoms of respiratory distress. The clinical signs of resp iratory distress in rBoIFNalpha1-treated cattle were significantly les s severe than those of the placebo group. The incidence rate, relapse rate and mean sick days of respiratory disease in the rBoIFNalpha1-tre ated group were 23%, 14% and 4.43 days, respectively, whereas those in the placebo group were 80%, 46% and 6.42 days, respectively. Furtherm ore, the mean increase of body weights in rBoIFNalpha1-treated group a nd placebo group were 1.365 kg/day and 1.340 kg/day, respectively. The se results suggest that rBoIFNalpha1 has a potentially preventive effe ct on the incidence of BRD.